ABSTRACT : Introduction: Negative pressure pulmonary edema is a clinical entity that is of great relevance in anaesthesiology and intensive care. The incidence of negative pressure pulmonary edema is less documented than it commonly occurs .this disorder is classified as type I and type II .type I usually occurs after onset of acute airway obstruction and type II after relief of chronic upper airway obstruction

METHODS : Case and discussion: We report the case of 58 year old female with a 2year history of neck swelling. She was diagnosed as having Graves disease and treated with Antithyroid drugs. There were no obvious eye signs and retrosternal extention Otorhinolaryngology examination ,ECG, thoracic inlet and chest X rays were normal. Patient underwent hemithyroidectomy, developed acute airway obstruction approximately 10 min after extubation Airway obstruction was unrelieved by Positive pressure ventilation using a face mask with an anesthetic breathing system. Trachea was reintubated, following that pink froth was noted coming out of ET tube. Vigorous inspiratory efforts against a completely obstructed airway, led to the development of acute negative pressure pulmonary edema.

RESULTS : Patient was treated with inj. Furosemide, Positive pressure ventilation and IV dexamethasone in intensive care unit. After 48 hrs of ventilation direct laryngoscopy and rigid bronchoscopy was done and the findings were normal. As there was no evidence of airway obstruction while breathing spontaneously patient was extubated and her post operative course was uneventful.

CONCLUSIONS : Conclusion: early detection and intervention of NPPV will decrease the morbidity and mortality